Faulty Front Heated Oxygen Sensor Bank 2
Front Heated Oxygen Sensor Bank 2 harness is open or shorted
Front Heated Oxygen Sensor Bank 2 circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks
Engine Light ON (or Service Engine Soon Warning Light)
High Fuel Consumption
Excessive Smoke from Exhaust
The Powertrain Control Module (PCM) supplies a voltage of about 450 mV between the HO2S high and low signal circuits. The oxygen sensor varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean.
The PCM monitors and stores the heated oxygen sensor (HO2S) voltage information. The PCM evaluates the HO2S voltage samples in order to determine the amount of time the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period and determines if majority of the samples are out of the operating range.